diff --git a/src/MuTalk-Tests/FixedRandomOperatorMutantSelectionTest.class.st b/src/MuTalk-Tests/FixedRandomOperatorMutantSelectionTest.class.st
deleted file mode 100644
index 2c3ee1a8..00000000
--- a/src/MuTalk-Tests/FixedRandomOperatorMutantSelectionTest.class.st
+++ /dev/null
@@ -1,97 +0,0 @@
-Class {
-	#name : #FixedRandomOperatorMutantSelectionTest,
-	#superclass : #RandomMutantSelectionTest,
-	#instVars : [
-		'coll'
-	],
-	#category : #'MuTalk-Tests'
-}
-
-{ #category : #running }
-FixedRandomOperatorMutantSelectionTest >> setUp [
-
-	| mutants |
-	super setUp.
-
-	coll := OrderedCollection new.
-	mutants := OrderedCollection new.
-	mutants addAll: {
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method1
-				 using: 'Operator1'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method1
-				 using: 'Operator2'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method1
-				 using: 'Operator3'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method2
-				 using: 'Operator1'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method2
-				 using: 'Operator2'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method2
-				 using: 'Operator3'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies) }.
-	coll addAll: mutants
-]
-
-{ #category : #tests }
-FixedRandomOperatorMutantSelectionTest >> testSelectMutantsFrom [
-
-	| select newColl |
-	select := FixedRandomOperatorMutantSelection new numberOfMutants: 3.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl size equals: 3
-]
-
-{ #category : #tests }
-FixedRandomOperatorMutantSelectionTest >> testSelectMutantsFrom2 [
-
-	| select newColl |
-	select := FixedRandomOperatorMutantSelection new numberOfMutants: 0.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl equals: {  } asOrderedCollection
-]
-
-{ #category : #tests }
-FixedRandomOperatorMutantSelectionTest >> testSelectMutantsFrom3 [
-
-	| select newColl |
-	select := FixedRandomOperatorMutantSelection new numberOfMutants: 6.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl equals: coll
-]
-
-{ #category : #tests }
-FixedRandomOperatorMutantSelectionTest >> testSelectMutantsFrom4 [
-
-	| select newColl |
-	select := FixedRandomOperatorMutantSelection new numberOfMutants: 10.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl equals: coll
-]
-
-{ #category : #tests }
-FixedRandomOperatorMutantSelectionTest >> testSelectMutantsFromDistinctElements [
-
-	| select newColl |
-	select := FixedRandomOperatorMutantSelection new numberOfMutants: 5.
-	newColl := select selectMutantsFrom: coll.
-	self
-		assert: newColl copyWithoutDuplicates asBag
-		equals: newColl asBag
-]
diff --git a/src/MuTalk-Tests/PercentRandomOperatorMutantSelectionTest.class.st b/src/MuTalk-Tests/PercentRandomOperatorMutantSelectionTest.class.st
deleted file mode 100644
index 389deb4a..00000000
--- a/src/MuTalk-Tests/PercentRandomOperatorMutantSelectionTest.class.st
+++ /dev/null
@@ -1,108 +0,0 @@
-Class {
-	#name : #PercentRandomOperatorMutantSelectionTest,
-	#superclass : #RandomMutantSelectionTest,
-	#instVars : [
-		'coll'
-	],
-	#category : #'MuTalk-Tests'
-}
-
-{ #category : #running }
-PercentRandomOperatorMutantSelectionTest >> setUp [
-
-	| mutants |
-	super setUp.
-
-	coll := OrderedCollection new.
-	mutants := OrderedCollection new.
-	mutants addAll: {
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method1
-				 using: 'Operator1'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method1
-				 using: 'Operator2'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method1
-				 using: 'Operator3'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method2
-				 using: 'Operator1'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method2
-				 using: 'Operator2'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies).
-			(MethodMutation
-				 for: AuxiliarClassForTestingStrategies >> #method2
-				 using: 'Operator3'
-				 nodeNumber: 1
-				 ofClass: AuxiliarClassForTestingStrategies) }.
-	coll addAll: mutants
-]
-
-{ #category : #tests }
-PercentRandomOperatorMutantSelectionTest >> testSelectMutantsFrom [
-
-	| select newColl |
-	select := PercentRandomOperatorMutantSelection new
-		          percentageOfMutants: 50.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl size equals: 3
-]
-
-{ #category : #tests }
-PercentRandomOperatorMutantSelectionTest >> testSelectMutantsFrom2 [
-
-	| select newColl |
-	select := PercentRandomOperatorMutantSelection new
-		          percentageOfMutants: 0.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl equals: {  } asOrderedCollection
-]
-
-{ #category : #tests }
-PercentRandomOperatorMutantSelectionTest >> testSelectMutantsFrom3 [
-
-	| select newColl |
-	select := PercentRandomOperatorMutantSelection new
-		          percentageOfMutants: 100.
-	newColl := select selectMutantsFrom: coll.
-	self assert: newColl equals: coll
-]
-
-{ #category : #tests }
-PercentRandomOperatorMutantSelectionTest >> testSelectMutantsFrom4 [
-
-	| select |
-	select := PercentRandomOperatorMutantSelection new.
-	self should: [ select percentageOfMutants: -50 ] raise: Error
-]
-
-{ #category : #tests }
-PercentRandomOperatorMutantSelectionTest >> testSelectMutantsFrom5 [
-
-	| select |
-	select := PercentRandomOperatorMutantSelection new.
-	self should: [ select percentageOfMutants: 150 ] raise: Error
-]
-
-{ #category : #tests }
-PercentRandomOperatorMutantSelectionTest >> testSelectMutantsFromDistinctElements [
-
-	| select newColl |
-	select := PercentRandomOperatorMutantSelection new
-		          percentageOfMutants: 90.
-	newColl := select selectMutantsFrom: coll.
-	self
-		assert: newColl copyWithoutDuplicates asBag
-		equals: newColl asBag
-]
diff --git a/src/MuTalk-Tests/RandomOperatorMutantSelectionTest.class.st b/src/MuTalk-Tests/RandomOperatorMutantSelectionTest.class.st
new file mode 100644
index 00000000..bb76d729
--- /dev/null
+++ b/src/MuTalk-Tests/RandomOperatorMutantSelectionTest.class.st
@@ -0,0 +1,151 @@
+Class {
+	#name : #RandomOperatorMutantSelectionTest,
+	#superclass : #TestCase,
+	#instVars : [
+		'coll'
+	],
+	#category : #'MuTalk-Tests'
+}
+
+{ #category : #running }
+RandomOperatorMutantSelectionTest >> setUp [
+
+	| mutants |
+	super setUp.
+
+	coll := OrderedCollection new.
+	mutants := OrderedCollection new.
+	mutants addAll: {
+			(MethodMutation
+				 for: AuxiliarClassForTestingStrategies >> #method1
+				 using: 'Operator1'
+				 nodeNumber: 1
+				 ofClass: AuxiliarClassForTestingStrategies).
+			(MethodMutation
+				 for: AuxiliarClassForTestingStrategies >> #method1
+				 using: 'Operator2'
+				 nodeNumber: 1
+				 ofClass: AuxiliarClassForTestingStrategies).
+			(MethodMutation
+				 for: AuxiliarClassForTestingStrategies >> #method1
+				 using: 'Operator3'
+				 nodeNumber: 1
+				 ofClass: AuxiliarClassForTestingStrategies).
+			(MethodMutation
+				 for: AuxiliarClassForTestingStrategies >> #method2
+				 using: 'Operator1'
+				 nodeNumber: 1
+				 ofClass: AuxiliarClassForTestingStrategies).
+			(MethodMutation
+				 for: AuxiliarClassForTestingStrategies >> #method2
+				 using: 'Operator2'
+				 nodeNumber: 1
+				 ofClass: AuxiliarClassForTestingStrategies).
+			(MethodMutation
+				 for: AuxiliarClassForTestingStrategies >> #method2
+				 using: 'Operator3'
+				 nodeNumber: 1
+				 ofClass: AuxiliarClassForTestingStrategies) }.
+	coll addAll: mutants
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testFixedSelectMutantsFrom [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection fixed: 3.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl size equals: 3
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testFixedSelectMutantsFrom2 [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection fixed: 0.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl equals: {  } asOrderedCollection
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testFixedSelectMutantsFrom3 [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection fixed: 6.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl equals: coll
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testFixedSelectMutantsFrom4 [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection fixed: 10.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl equals: coll
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testFixedSelectMutantsFromDistinctElements [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection fixed: 5.
+	newColl := select selectMutantsFrom: coll.
+	self
+		assert: newColl copyWithoutDuplicates asBag
+		equals: newColl asBag
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testPercentSelectMutantsFrom [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection percent: 50.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl size equals: 3
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testPercentSelectMutantsFrom2 [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection percent: 0.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl equals: {  } asOrderedCollection
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testPercentSelectMutantsFrom3 [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection percent: 100.
+	newColl := select selectMutantsFrom: coll.
+	self assert: newColl equals: coll
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testPercentSelectMutantsFrom4 [
+
+	self
+		should: [ RandomOperatorMutantSelection percent: -50 ]
+		raise: Error
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testPercentSelectMutantsFrom5 [
+
+	self
+		should: [ RandomOperatorMutantSelection percent: 150 ]
+		raise: Error
+]
+
+{ #category : #tests }
+RandomOperatorMutantSelectionTest >> testPercentSelectMutantsFromDistinctElements [
+
+	| select newColl |
+	select := RandomOperatorMutantSelection percent: 90.
+	newColl := select selectMutantsFrom: coll.
+	self
+		assert: newColl copyWithoutDuplicates asBag
+		equals: newColl asBag
+]